Process of clarifying aqueous solutions.



To all whom it may concern:

' uct necessarily result.

-method of subjecting water to the action of JEAN A. MAIGNEN, orPHILADELPHIA, PENNSYLVANIA.

'PROCESS OF CLARIFYING AQUEOUS SOLUTIONS.

Specification of Letters Patent.

Application filed April 18. 1900- Serial No. 13.293.

Patented Dec. 31, 190'?o Be it known that .I, JEAN A. MAIGNEN, ofPhiladelphia, in the State of Pennsylvania,

have invented certain new and useful Improvements in Process ofClarifying Aqueous- $olutions, whereofthe following is a specification.

My invention relates to processes of clarification wherein chemicals areemployed to coagulatethe matter suspendedin water.

Ordinarily the water to be clarified is subj 'ected to the action of thecoagulant in either one of two ways, that most commonly employedbeing-to primarily dissolve .the coagulant in a given quantity of water,and to then add the liquefied coagulant to the'water to be clarified; Itis'found in practice that such a process gives results which are farfrom uniform or satisfactory, for the reason that when freshly made andagitated in a tank, the liquefied coagulant may be of the same densitythroughout, but immediately becomes denser at the bottom'and lighter atthe top, when the agitation ceases, so that the strength of theliquefied coagulant added :to the water at a given instant, is dependentupon the particular strata from which it is withdrawn, and correspondingirregularities of coagulating action and effluent prod- The secondordinary the coagulant, is to place the latter in crystal 'form in aninclosure, through which the Water to be clarified. is caused to flow.It is found in practice that under such circumstances the coagulatingaction is irregular in correspondence with the quantity of thecrystallized coagulant presented at a given instant to the flow ofwater, such action being of course stronger when the inclosure is quitefull than when a part of the coagulatlng crystals have been dissolved,and carried away. It is characteristic of both of the well knownprocesses aforesaid, that at times the effluent contains four or fivetimes the quantity of the coagulant whichis actually requiredffor thepurpose of clarification,

and at other times, the effluent does not contain sufficient of thecoagulant to effect the clarification.

' It is the object of my invention to secure the uniform clarificationof given quantities of water with a minimum expenditure of chemicals,and to this end, my improvedprocess consists in adding to the water, tobe treated, a plurality of distinct chemicals in ers, etc.

a dry comminuted state, in predetermined quantities, and in suchrelation that the water is subjected to thecombined coagulating actionof said chemicals; said chemicals being sulfate of alumina, and sodaash, preferably mixed in the proportion of 2.9 of the former to 3.1 ofthe latter. v

I am aware that sulfate of alumina and alum have been hitherto used forthe clarification of water; it has been found in practice however, thatapart thereof combines with lime present in the water and forms sulfateof lime, rendering the efiiuent not only prejudicial to health, but alsocommercially undesirable, by reason of its incrustation of boil- I havefound thatwhen the two reagents above specified are used in thepreferred pro 'ortions, they neutralize one ariother, so t at even if anexcess of the combination thereof be added to the water, the latterafter treatment, is neither acids or alkaline. The full benefit of allof the possible chemical decompositions and reactions is obtained whensaid two chemicals. in a dry comminuted form, are added to the watersimultaneously. The carbonic acid which is immediately liberated servesnot only to agi tate all the body of the water by its tendency to rise,but also helps to more completely distribute the precipitate andincrease its coagu lating effect.

Although it is desirable that the process herein described be carriedout in apparatus comprising means to automatically predetermine. thequantities of the chemicals added to the water, in course of treatment,it is obvi- A equivalent thereof.

I claim: A f 1. The -hereinbefore described process of producingpractically neutral potable water which consists in subjecting softdirty water to the contemporaneous action of sulfate of alumina and sodaash, mixed indefinite proportions,by adding said chemicals in a drycomminuted state to the Water, substantially as set forth.

' 2. The hereinbefore describedv rocess of producing practically neutralpota le water,

i 10 in a dry comminuted state to t e water, substantially asset forth.

soda ash, in a dry comminuted state, previ- 15 -ously mixed inpredetermined definite proportions, substantially. as set forth. 7

' JEAN A. MAIGNEN.

Witnesses: i

' ARTHUR E. PAIGE;

E, L. FULLERTON.

